Subtle grey matter changes between migraine patients and healthy controls.

Local morphological alterations of the brain have recently been detected in cluster headache and chronic tension-type headache, but not in migraine. We investigated 35 patients suffering from migraine and compared them with 31 healthy controls with no headache history. Using magnetic resonance imaging and voxel based morphometry, we found a significant decrease of grey matter in areas ascribable to the transmission of pain (cingulate cortex), but not in areas specific for migraine, such as the brainstem. Our data are in line with recent findings in chronic pain states, such as chronic phantom pain and chronic back pain. We suggest that the grey matter change in migraine patients is the consequence of frequent nociceptive input and should thus be reversible when migraine attacks cease.